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Swing Check valve

Swing Check valve

The swing check valve is a high-performance non-return valve designed for robust backflow prevention in industrial pipelines, ensuring unidirectional flow for water, oil, gas, and chemical systems.

Swing Check valve

The swing check valve is a high-performance non-return valve designed for robust backflow prevention in industrial pipelines, ensuring unidirectional flow for water, oil, gas, and chemical systems.

What is Swing Check Valve?

Swing check valves are among the most widely used types of check valves. They ensure reliable one-way flow, preventing backflow with a simple and robust design. The swinging disc offers minimal resistance and allows full, unobstructed flow.

Working Principle

A swing check valve consists of a body, a bonnet, and a hinged disc. The disc swings away from the seat to permit forward flow, and returns to the seat when upstream flow stops, automatically preventing backflow.

Design Features
  • ✔ Unguided disc for full open/close movement
  • ✔ Available in multiple disc & seat designs
  • ✔ Full, unobstructed flow path
  • ✔ Automatically closes as pressure decreases
  • ✔ Low turbulence and minimal pressure drop

The Swing Check Valve is a high-performance non-return valve designed for robust backflow prevention in industrial pipelines, ensuring unidirectional flow for water, oil, gas, and chemical systems. Featuring a hinged disc that swings open with forward flow and closes automatically against reverse flow, this valve protects pumps, compressors, and piping from damage caused by backpressure. Constructed from durable materials like ASTM A216 WCB carbon steel, ASTM A351 CF8M stainless steel, or ductile iron, with optional coatings such as epoxy or 3LPE, it offers exceptional corrosion resistance, making it ideal for backflow prevention valve applications in oil and gas, water treatment, and power generation industries.

Compliant with API 594 for check valves and ASME B16.34 for manufacturing, the swing check valve is available in sizes from 2" to 60" (DN50 to DN1500) with flanged, wafer, or butt-weld end connections per ASME B16.5 and B16.25. It supports pressure ratings up to PN40 (ANSI Class 150-600) and temperatures from -29°C to 425°C, with seat options like metal-to-metal for high temperatures or resilient EPDM/Viton for bubble-tight sealing in low-pressure systems. The full-bore design minimizes pressure drop (Cv values up to 15,000), optimizing flow efficiency in high-throughput industrial flow control applications. Certifications such as API 6D for pipeline valves, NSF 61 for potable water, and NACE MR0175 for sour service ensure versatility and reliability.

The valve’s robust construction includes a one-piece body and a heavy-duty hinge pin, reducing leak paths and ensuring durability under high-pressure conditions. Its corrosion resistant swing valve properties are enhanced by coatings that protect against rust, chlorides, and abrasive media, extending service life up to three times longer than uncoated valves in harsh environments like seawater or chemical processing. Rigorous testing per API 598, including hydrostatic shell tests at 1.5x rated pressure and seat leakage verification, confirms zero-leakage performance, while nondestructive examinations (RT, UT, MT) ensure structural integrity. With tensile strengths above 485 MPa, the valve withstands cyclic loading and thermal cycling in non-return valve duties.

Compared to dual-plate or lift check valves, the swing check valve offers a simpler design with lower maintenance needs, particularly in large-diameter, high-flow systems. Its gravity-assisted or spring-loaded disc ensures reliable closure without external actuation, reducing operational costs in backflow prevention valve setups. Optional features like renewable seats, soft seals for low-pressure applications, or extended bonnets for high-temperature insulation enhance adaptability for petrochemical refineries, HVAC systems, and marine pipelines. The valve’s ability to handle viscous fluids and slurries without chattering makes it a preferred choice for demanding applications.

Addressing challenges like backflow contamination, pipeline erosion, and equipment failure, the swing check valve incorporates a robust hinge mechanism and durable seals to ensure long-term performance. Its compatibility with global flange standards (ANSI, DIN, JIS) and coatings like FBE or PTFE ensures applicability in diverse environments, from buried pipelines to offshore platforms. Whether preventing reverse flow in boiler feed systems or protecting municipal water lines, the Swing Check Valve delivers cost-effective, reliable industrial flow control with minimal maintenance for global industrial operations.

FAQs

Engineered for robust backflow prevention with durable materials and low-maintenance design.

Its hinged disc ensures rapid closure against reverse flow, ideal for backflow prevention valve applications.

Yes, it supports up to PN40 and ANSI Class 600 for reliable industrial flow control.

It meets API 594, ASME B16.34, API 598, and NSF 61 for corrosion resistant swing valve performance.

Swing check valve offers simpler maintenance and higher flow capacity for large non-return valve systems.

Key Features of a Check Valve

Check valves are essential components that ensure safe and efficient operation of fluid systems by controlling flow direction and preventing backflow.

Flow Direction Control

Permits fluid flow in one direction and automatically closes to prevent backflow in the opposite direction.

Mechanical Design

Uses hinged or spring-loaded flaps, discs, or pistons that open with forward flow and close with backflow.

Various Types

Includes swing, lift, ball, and diaphragm check valves, each suited for different applications and conditions.

Versatility

Widely used in water, wastewater, oil & gas, HVAC, and many other industrial applications.

Preventing Water Hammer

Helps avoid sudden pressure surges caused when fluid flow is abruptly stopped.

Low Maintenance

Simple and reliable design ensures long-term efficiency with minimal upkeep.

Check Valves & Backflow Prevention

Check valves are one-way valves that allow fluid to flow in a single direction and automatically prevent backflow. They are widely used in pipelines to protect pumps, piping, and other equipment. Backflow preventers apply additional pressure to ensure water flows only one way, providing extra protection for drinking water systems.

What is a Check Valve?

Allows fluid to flow in one direction and automatically prevents backflow.
Protects pumps, piping, and other equipment.

Check Valve vs Backflow Preventer

Check Valve: Simple, hinged or spring-loaded disc.
Backflow Preventer: Uses pressure and fail-safes to protect drinking water.

Swing Check Valve

Hinged disc swings open to allow forward flow and closes to prevent backflow.
Low turbulence and low pressure drop.

Lift Check Valve

Piston or ball lifts from the seat to allow flow.
Suitable for high-pressure and high-velocity systems; can be installed horizontally or vertically.

Other Types

Ball Check, Butterfly Check, and Tilting-Disk Check valves.
Each design is optimized for specific applications and conditions.

Key Features

- Unidirectional flow control
- Low maintenance
- Prevents water hammer
- Wide range of sizes & materials
- Versatile in water, oil, gas, and HVAC systems

Check Valve vs Backflow Preventer

Feature Check Valve Backflow Preventer
Primary Function Allows flow in one direction; prevents reverse flow automatically Prevents contamination of drinking water; ensures flow only in one direction using pressure & fail-safes
Mechanical Design Hinged disc, flap, piston, or ball opens with flow and closes with backflow Multiple valves, check mechanisms, or air gaps to enforce one-way flow
Application Pipelines, pumps, HVAC, water & wastewater, oil & gas Potable water supply, irrigation, hospitals, schools, commercial buildings
Pressure Handling Medium to high pressure; depends on valve type High reliability; designed for pressurized systems to prevent contamination
Maintenance Low; simple design, few moving parts Moderate; more components, periodic inspection recommended
Reliability Good for general use; may fail under extreme conditions Highly reliable; multiple fail-safes for drinking water protection

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General Standards of Valves

Comprehensive list of key international valve standards from major organizations, updated as of 2025.

Organization Standard Description
ANSI American National Standards Institute General industrial standards
API American Petroleum Institute Standards for oil and gas industry
ASME American Society of Mechanical Engineers Boiler and pressure vessel codes
BS British Standards UK national standards
GB, JB, HG China Valve Standards Chinese national and industry standards
FCI Fluid Control Institute Standards for fluid control and conditioning equipment
What is a valve?

ANSI Valve Standards

American National Standards Institute

Code ANSI Standard Name
ANSI A126 Grey Iron Castings for Valves, Flanges, and Pipe Fittings
ANSI A181 Forged or Rolled Steel Pipe Flanges, Forged Fittings, and Valves and Parts for General Service
ANSI B16.10 Face-to-Face and End-to-End Dimensions of Valves
ANSI B16.34 Valves - Flanged, Threaded, and Welding End
ANSI B16.5 Pipe Flanges and Flanged Fittings
ANSI/FCI 70-2 Control Valve Seat Leakage
ANSI B127.1 Constant-Level Oilers

API Valve Standards

American Petroleum Institute

Code API Standard Name
API 526 Flanged Steel Pressure-Relief Valves
API 527 Seat Tightness of Pressure Relief Valves
API 594 Check Valves: Flanged, Lug, Bolted Bonnet
API 595 Cast Iron Gate Valves - Flanged Bonnet
API 597 Steel Venturi Gate Valves - Flanged and Welding Ends
API 598 Valve Inspection and Testing
API 599 Steel and Ductile Iron Plug Valves
API 600 Bolted Bonnet Steel Gate Valves for Refinery Service
API 602 Compact Steel Gate Valves - Flanged, Threaded, and Welding Ends
API 603 Corrosion-Resistant Gate Valves - Flanged Ends
API 604 Ductile Iron Gate Valves - Flanged Ends
API 607 Fire Test for Quarter-Turn Valves
API 608 Metal Ball Valves - Flanged, Threaded, and Welding Ends
API 609 Butterfly Valves: Double Flanged, Lug- and Wafer-Type
API 6D Pipeline and Piping Valves
API 6FA Fire Test for Valves
API RP 574 Inspection Practices for Piping System Components
API RP 576 Inspection of Pressure-Relieving Devices

ASME Valve Standards

American Society of Mechanical Engineers

Code ASME Standard Name
ASME A105/A105M Carbon Steel Forgings for Piping Applications
ASME A181/A181M Carbon Steel Forgings, for General-Purpose Pipes
ASME A182/A182M Forged or Rolled Alloy and Stainless Steel Pipe Flanges, Forged Fittings, and Valves and Parts for High-Temperature Service
ASME A350/A350M Carbon and Low-Alloy Steel Forgings for Low-Temperature Service
ASME A694/A694M Carbon and Alloy Steel Forgings for Pipe Flanges, Fittings, Valves, and Parts for High-Pressure Transmission Service
ASME B16.5 Pipe Flanges and Flanged Fittings: NPS 1/2 Through NPS 24 Metric/Inch Standard
ASME B16.10 Face-to-Face and End-to-End Dimensions of Valves
ASME B16.11 Forged Fittings, Socket-Welding and Threaded
ASME B16.34 Valves - Flanged, Threaded, and Welding End
ASME B31.1 Power Piping
ASME B31.3 Process Piping
ASME F1508 Standard Specification for Angle Style, Pressure Relief Valves for Steam, Gas, and Liquid Services
ASME F1565 Pressure-Reducing Valves for Steam Service

BS - British Standard Valves

British Standards Institution

Code British Standard Name
BS 1212 Float Operated Valves - Automatic Valves (Including Float Valves) for Tanks, Cisterns, Hot-Water Cylinders and Feed Cisterns
BS 1414 Specification for Steel Wedge Gate Valves (Flanged and Butt-Welding Ends) for the Petroleum, Petrochemical and Allied Industries
BS 1552 Specification for Control Plug Cocks for Low Pressure Gases
BS 1868 Specification for Steel Check Valves (Flanged and Butt-Welding Ends) for the Petroleum, Petrochemical and Allied Industries
BS 1873 Specification for Steel Globe and Globe Stop and Check Valves (Flanged and Butt-Welding Ends) for the Petroleum, Petrochemical and Allied Industries
BS 1952 Specification for Copper Alloy Gate Valves for General Purposes
BS 2080 Specification for Face-to-Face, Centre-to-Face, End-to-End and Centre-to-End Dimensions for Flanged and Butt-Welding End Steel Valves for the Petroleum, Petrochemical and Allied Industries
BS 2995 Specification for Cast and Forged Steel Wedge Gate, Globe, Check and Plug Valves Screwed and Socket-Welding Sizes 1/2 in and Smaller for the Petroleum Industry
BS 3464 Specification for Cast Iron Gate Valves for General Purposes
BS 5150 Specification for Cast Iron Wedge and Double Disk Gate Valves for General Purposes
BS 5151 Specification for Cast Iron Gate (Parallel Slide) Valves for General Purposes
BS 5152 Specification for Cast Iron Globe and Globe Stop and Check Valves for General Purposes
BS 5153 Specification for Cast Iron Check Valves for General Purposes
BS 5154 Specification for Copper Alloy Globe, Globe Stop and Check, Check and Gate Valves for General Purposes
BS 5155 Specification for Butterfly Valves for General Purposes
BS 5156 Specification for Screw-Down Diaphragm Valves for General Purposes
BS 5157 Specification for Steel Gate (Parallel Slide) Valves for General Purposes
BS 5159 Specification for Cast Iron and Carbon Steel Ball Valves for General Purposes
BS 5160 Specification for Steel Globe Valves, Globe Stop Valves, Stop and Check Valves and Lift Type Check Valves
BS 5351 Specification for Steel Ball Valves for Petroleum, Petrochemical and Allied Industries
BS EN 12266-1 Industrial Valves - Testing of Metallic Valves Part 1: Pressure Tests - Test Procedures

China and International Valve Standards (GB)

China National Standards

Code GB Standard Name Adopting Standard
GB 12220 General Valve - Marking ISO 5209
GB 12221 Flanged Ends Metal Valve - Face-to-Face Dimensions ISO 5752
GB 12222 Multi-Turn Valve - The Connection of the Driving Device ISO 5210/1-3
GB 12223 Part-Turn Valve - The Connection of the Driving Device ISO 5211/1-3
GB 12224 Steel Valve - General Requirements ANSI B16.34
GB 12225 General Valve - Copper Alloy Casting Ware Technology Requirements ASTM B584
GB 12226 General Valve - Gray Cast Iron Technology Requirements ISO 185, BS 1452
GB 12228 General Valve - Carbon Forging Steel Technology Requirements ASTM A105, A181
GB 12229 General Valve - Carbon Casting Steel Technology Requirements ASTM A703
GB 12230 General Valve - Austenitic Casting Steel Technology Requirements ASTM A351
GB 12232 General Valve - Flanged Ends Iron Gate Valve ISO 5996-1982, API 595
GB 12233 General Valve - Iron Gate Valve and Lift Check Valve BS 5152, 5153
GB 12234 General Valve - Flanged and Butt-Welding Ends Copper Gate Valve API 600
GB 12237 General Valve - Flanged and Butt-Welding Ends Steel Ball Valve ISO 7121, API 607
GB 12238 General Valve - Flanged and Wafer Ends Butterfly Valve BS 5155
GB 12239 General Valve - Diaphragm Valve BS 5156, NFE 29
GB 12240 General Valve - Iron Plug Valve API 593
GB 12241 Safety Valve - General Requirements ISO 4126
GB 12242 Safety Valve - Characteristic Testing Solution ANSI/ASME PTC 25.3
GB 12243 Direct Spring-Loaded Safety Valve JIS B 8210
GB 12244 Pressure Reducing Valve - General Requirements JIS B 8372, B8410
GB 12245 Pressure Reducing Valve - Characteristic Testing Solution JIS B 8372, B8410
GB 12246 Pilot Operated Pressure Reducing Valve JIS B 8372, DSS 405
GB 12247 Steam Trap Valve - Classification ISO 6704
GB 12248 Steam Trap Valve - Technology Terms ISO 6552
GB 12249 Steam Trap Valve - Marking ISO 6553
GB 12250 Steam Trap Valve - Face-to-Face Dimensions ISO 6554
GB 12251 Steam Trap Valve - Testing Solution ISO 6948, 7841, 7842
GB/T 13927 General Valve - Pressure Testing ISO 5208
JB/T 6899-93 Valve Fire-Proof Test ISO 10497
JB/T 7927-95 Valve Casting Steelware Out-Form Quality Requirements MSS SP-55
ZBJ 16006-90 Inspection and Testing of Valve API 598
Code GB Standard Name
GB 12227 General Valve - Ductile Cast Iron Technology Requirements
GB 12235 General Valve - Flanged Steel Stop and Lift Check Valve
GB 12236 General Valve - Steel Swing Check Valve
GB/T 13932 General Valve - Iron Swing Check Valve
GB/T 15185 Iron and Copper Ball Valve
GB/T 15188.1 Valve Face-to-Face Dimensions - Butt-Welding Ends Valve
GB/T 15188.2 Valve Face-to-Face Dimensions - Wafer Ends Valve
GB/T 15188.3 Valve Face-to-Face Dimensions - Female Screw-Down Valve
GB/T 15188.4 Valve Face-to-Face Dimensions - Male Screw-Down Valve
JB 93 Handle
JB/T 450 PN16-32.0 MPa Forging Angle Type High-Pressure Valve, Fastener, and Technology Requirements
JB/T 7745-95 Pipeline Ball Valve
JB/T 8527-97 Metal Sealing Butterfly Valve
JB/T 8473-96 Instrument Valve Series
ZBJ 16004-88 Reducing Valve Type and Basing Coefficient
ZBJ 16007-90 Steam Trap Valve Technology Terms
ZBJ 16009-90 Valve Pneumatic Actuator Technology Terms

Fluid Control Institute (FCI) Standards

Standards for fluid control and conditioning equipment

The Fluid Control Institute (FCI) provides standards to assist in understanding and using control valves, solenoid valves, and regulators.

Code FCI Standard Name
ANSI/FCI 70-2 Control Valve Seat Leakage
ANSI/FCI 70-3 Control Valve Aerodynamic Noise Prediction
ANSI/FCI 91-1 Qualification of Control Valve Stem Seals
ANSI/FCI 85-1 Method of Determining the Thermal Expansion of a Filled Thermal System
FCI 68-2 Procedure in Rating Flow and Pressure Characteristics of Solenoid Valves for Liquid Service
FCI 75-1 Test Conditions and Procedures for Measuring Electrical Characteristics of Solenoid Valves
FCI 82-1 Recommended Methods for Testing and Classifying the Water Hammer Characteristics of Electrically Operated Valves
ANSI/FCI 69-1 Pressure Ratings of Traps

Industrial Applications

Oil & Gas

Upstream, midstream, and downstream operations, including drilling, refining, and transportation.

Chemical Processing

Handling corrosive and hazardous chemicals in various chemical plants.

Power Generation

Steam, water, and fuel systems in thermal, nuclear, and hydroelectric plants.

Water Treatment

Municipal water supply, wastewater treatment, and industrial water management.

HVAC

Heating, ventilation, and air conditioning systems in commercial and industrial buildings.

Pharmaceutical & Food

Sterile and hygienic applications, precise flow control in sensitive industries.

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